The present invention relates in general to mechanisms for releasably supporting a structure and, more particularly, to an offset printing press feed table release mechanism, such release mechanism being tripped by an easily and safely accessible release knob to permit dropping of the feed table to a lowered position to facilitate access to the interior of the printer head of the press.
As taught by U.S. Pat. No. 3,218,064 to Davidson, Jr. et al, the entirety of which is herein incorporated by reference, it is known in the art to support the printer head-adjacent end of an offset press feed table by means of a release mechanism. The Davidson, Jr. et al release mechanism is tripped by a latch handle generally within the paper feed path above the paper feed conveyor and immediately adjacent the printer head housing which contains the rotating printing cylinders. In reaching to trip the release mechanism by means of the latch handle, the press operator may inadvertently allow portions of his hand to enter the printing head housing containing the rotating printing cylinders. Further, as the operator reaches for the Davidson, Jr. et al latch handle, a loose shirt sleeve or the like may snag on the paper feed conveyor and pull the operator's arm into the printer head housing. Finally, movement of the Davidson, Jr. et al latch handle to a release position requires that the handle be moved toward the rotating cylinders within the printing head. It can be appreciated that such a dangerous condition can result in severe injuries to the press operator's hand.
With reference to the Davidson, Jr. et al release mechanism itself, the movable portions of the release mechanism, i.e., catch members 41,42, are fixed to and mounted on each side of the printer head housing. Each catch member supports a side of the feed table end adjacent the printer head. To provide for concurrent movement of the catch members 41, 42 for effective release of the table, a rotatable shaft 46 extends between the catch members across the paper entry opening of the printer head. It can be seen that the shaft 46 impedes access to the printing cylinders once the table is dropped to its lowered position.
A release mechanism avoiding the safety problem as noted above, which would facilitate access to the printing head cylinders, while highly desirable, must also be reliable and of relative simplicity to meet cost goals.